Hi,
There does appear to be one difference. It looks like this model uses
the assumption that R20A = R20B = R20 (or in the original notation,
R2G = R2E = R2). The R1G, R1E, and R2E values are not used in the
code. So I assume that it should give the same result as the reduced
models as I have now created in relax from the fitting_main_kex.py
code rather than the full R20A != R20B models. So if the spin-spin
relaxation rates for the two states are significantly different, then
this model should not be able to reproduce the results of the other
models in fitting_main_kex.py. Though maybe I have missed something?
Cheers,
Edward
On 17 July 2013 15:35, Paul Schanda <paul.schanda@xxxxxx> wrote:
Hi Edward,
No, there is nothing published. Nikolai said that anyways it's trivial :-)
He derived it basically by putting the Bloch-McConnell equations to Maple
and simplifying it there. I guess there is something like a FullSimplify
(that's Mathematica-style, but I guess Maple does it similarly).
I guess the main advantage is speed, and in fact in all cases I have seen it
does exactly the same as the explicit Bloch-McConnell treatment, so I see it
as the treatment that one would like to use.
I agree that having something undocumented there is not particularly nice,
but in the end it's up to the user whether or not to use this faster
treatment (and compare it to the slower Bloch-McConnell one if needed).
paul
On 17.07.13 15:14, Edward d'Auvergne wrote:
Hello,
I am now adding the numerical dispersion model derived by Nikolai
Skrynnikov to relax. This is model 5 from the fitting_main_kex.py
script (for reference attached to https://gna.org/task/?7712). I was
wondering if there was a published reference for this that you know
of? This would be useful for the model name and for the
documentation.
Cheers,
Edward
--
Paul Schanda, Ph.D.
Biomolecular NMR group
Institut de Biologie Structurale Jean-Pierre Ebel (IBS)
41, rue Jules Horowitz
F-38027 Grenoble
France
+33 438 78 95 55
paul.schanda@xxxxxx
http://www.ibs.fr/groups/biomolecular-nmr-spectroscopy?lang=en
Re: Reference for the Skrynnikov derivation?